Pose mode- can't change transform location of root bone?
Looking at your file this problem is because the root bone Bone.27 is set to Connected. You need to unset this. To do this follow the below steps:

Switch to Edit Mode
Select the root bone Bone.27
Go to the Bone tab in the properties window
Uncheck the Connectedcheck box in the relations panel


This will fix the problem and you will be able to grab the root bone and move the character using it as shown below:

Updated .blend file can be found here: